A national park is a refuge for the animals and plants living in it. Even if your pet does not chase deer, birds, or ground critters, it still presents the image and scent of a historical predator. The result is stress on the native wildlife. In addition, predators such as owls, coyotes, mountain lions, and javelinas can and do kill pets. Even large dogs cannot defend themselves against predators. Contagious diseases can also be transmitted between your dog and native coyotes and other wild animals.
Having a pet with you may limit some of your activities and explorations in the park. Abiding by these pet regulations will ensure a safer, more enjoyable visit for yourselves, other park visitors, your pet, and the park's wildlife.